From: Sabyrzhan Tasbolatov <snovitoll@gmail.com>
To: rydberg@bitmath.org, dmitry.torokhov@gmail.com
Cc: linux-input@vger.kernel.org, linux-kernel@vger.kernel.org,
syzbot+0122fa359a69694395d5@syzkaller.appspotmail.com
Subject: [PATCH] drivers/mt: restrict length of kzalloc in input_mt_init_slots()
Date: Tue, 2 Feb 2021 18:08:07 +0600 [thread overview]
Message-ID: <20210202120807.1394788-1-snovitoll@gmail.com> (raw)
syzbot found WARNING in input_mt_init_slots [1] when
struct_size(mt, slots, num_slots)=0x40006 where num_slots=0x10001,
which exceeds KMALLOC_MAX_SIZE (0x40000) and causes
order >= MAX_ORDER condition.
[1]
Call Trace:
alloc_pages_current+0x18c/0x2a0 mm/mempolicy.c:2267
alloc_pages include/linux/gfp.h:547 [inline]
kmalloc_order+0x2e/0xb0 mm/slab_common.c:837
kmalloc_order_trace+0x14/0x120 mm/slab_common.c:853
kmalloc include/linux/slab.h:557 [inline]
kzalloc include/linux/slab.h:682 [inline]
input_mt_init_slots drivers/input/input-mt.c:49 [inline]
Reported-by: syzbot+0122fa359a69694395d5@syzkaller.appspotmail.com
Signed-off-by: Sabyrzhan Tasbolatov <snovitoll@gmail.com>
---
drivers/input/input-mt.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/input/input-mt.c b/drivers/input/input-mt.c
index 44fe6f2f063c..e542f45a45ab 100644
--- a/drivers/input/input-mt.c
+++ b/drivers/input/input-mt.c
@@ -40,13 +40,18 @@ int input_mt_init_slots(struct input_dev *dev, unsigned int num_slots,
{
struct input_mt *mt = dev->mt;
int i;
+ size_t mt_size = 0;
if (!num_slots)
return 0;
if (mt)
return mt->num_slots != num_slots ? -EINVAL : 0;
- mt = kzalloc(struct_size(mt, slots, num_slots), GFP_KERNEL);
+ mt_size = struct_size(mt, slots, num_slots);
+ if (mt_size > KMALLOC_MAX_SIZE)
+ return -ENOMEM;
+
+ mt = kzalloc(mt_size, GFP_KERNEL);
if (!mt)
goto err_mem;
--
2.25.1
next reply other threads:[~2021-02-02 12:10 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-02 12:08 Sabyrzhan Tasbolatov [this message]
2021-02-26 8:42 ` [PATCH] drivers/mt: restrict num_slots in input_mt_init_slots() Sabyrzhan Tasbolatov
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210202120807.1394788-1-snovitoll@gmail.com \
--to=snovitoll@gmail.com \
--cc=dmitry.torokhov@gmail.com \
--cc=linux-input@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=rydberg@bitmath.org \
--cc=syzbot+0122fa359a69694395d5@syzkaller.appspotmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).